1. Field of the Invention
The present invention relates to photolithographic techniques for use in fabricating integrated circuits.
2. Description of the Related Art
Photolithography is a photographic process used to transfer circuit patterns onto a semiconductor wafer. The process generally involves projecting light through a patterned mask onto a silicon wafer which is covered with a photosensitive film, e.g., photoresist. A stepper move across the mask, projecting light through the mask to image portions of the photoresist corresponding to the mask pattern. The wafer is then developed so that the exposed or unexposed portions of the photoresist are removed, depending on the type of resist used. While photolithography is a relatively mature technology, new challenges are encountered by the ever present desire to scale down feature sizes.